SDHB and paraganglioma: This phenomenon, distinct from the global DNA hypermethylation of SDH-deficient GISTs as a whole, is common to most SDH-deficient, SDHx-WT GISTs, irrespective of CT presence; however, “non-CT” cases could be formes frustes of CT, as suggested by the mosaic constitutional SDHC promoter hypermethylation, implying a risk for metachronous paraganglioma/pulmonary chondroma [105].